Ambivalence-dependent alterations in brain function during self-evaluation in adults with depressive symptoms.

Although patients with depression frequently report distorted self-related beliefs, such as all-or-nothing thinking, little is known about disruptions in behavioural and brain processes that occur when adults with depression make such self-evaluations. Here, we examined 117 participants ranging in depression severity (from non- to severely depressed) as they rated their belief in statements about themselves or famous people during fMRI. We used mixed-effects models to examine task characteristics (e.g. self vs other) and depression severity to test our hypotheses that during self-evaluation, adults with depression would show increased all-or-nothing thinking (i.e. decreased responding in the middle of the scale), slower reaction times (RTs), and increased brain activation and connectivity in cortical regions involved in self-evaluation. Greater depression severity was associated with increased ambivalence (decreased all-or-nothing thinking) overall. Furthermore, RTs during low-ambivalence judgements increased with depression severity. Depression severity was also linked to altered brain function, including decreased activation during low-ambivalence self-evaluation (vs other) in the medial prefrontal cortex, superior frontal cortex, and the perigenual anterior cingulate cortex (pgACC). Additionally, the pgACC displayed increased activation during high-ambivalence self-evaluation (vs other). Our findings clarify how adults with depression evaluate self-related beliefs, which may inform novel treatments to target distortions in these beliefs.